1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 /*
18 * Encapsulate a mutex for thread synchronization.
19 */
20
21 #include "Mutex.h"
22 #include "NfcJniUtil.h"
23
24 #include <cutils/log.h>
25 #include <errno.h>
26 #include <string.h>
27
28 /*******************************************************************************
29 **
30 ** Function: Mutex
31 **
32 ** Description: Initialize member variables.
33 **
34 ** Returns: None.
35 **
36 *******************************************************************************/
Mutex()37 Mutex::Mutex ()
38 {
39 memset (&mMutex, 0, sizeof(mMutex));
40 int res = pthread_mutex_init (&mMutex, NULL);
41 if (res != 0)
42 {
43 ALOGE ("Mutex::Mutex: fail init; error=0x%X", res);
44 }
45 }
46
47
48 /*******************************************************************************
49 **
50 ** Function: ~Mutex
51 **
52 ** Description: Cleanup all resources.
53 **
54 ** Returns: None.
55 **
56 *******************************************************************************/
~Mutex()57 Mutex::~Mutex ()
58 {
59 int res = pthread_mutex_destroy (&mMutex);
60 if (res != 0)
61 {
62 ALOGE ("Mutex::~Mutex: fail destroy; error=0x%X", res);
63 }
64 }
65
66
67 /*******************************************************************************
68 **
69 ** Function: lock
70 **
71 ** Description: Block the thread and try lock the mutex.
72 **
73 ** Returns: None.
74 **
75 *******************************************************************************/
lock()76 void Mutex::lock ()
77 {
78 int res = pthread_mutex_lock (&mMutex);
79 if (res != 0)
80 {
81 ALOGE ("Mutex::lock: fail lock; error=0x%X", res);
82 }
83 }
84
85
86 /*******************************************************************************
87 **
88 ** Function: unlock
89 **
90 ** Description: Unlock a mutex to unblock a thread.
91 **
92 ** Returns: None.
93 **
94 *******************************************************************************/
unlock()95 void Mutex::unlock ()
96 {
97 int res = pthread_mutex_unlock (&mMutex);
98 if (res != 0)
99 {
100 ALOGE ("Mutex::unlock: fail unlock; error=0x%X", res);
101 }
102 }
103
104
105 /*******************************************************************************
106 **
107 ** Function: tryLock
108 **
109 ** Description: Try to lock the mutex.
110 **
111 ** Returns: True if the mutex is locked.
112 **
113 *******************************************************************************/
tryLock()114 bool Mutex::tryLock ()
115 {
116 int res = pthread_mutex_trylock (&mMutex);
117 if ((res != 0) && (res != EBUSY))
118 {
119 ALOGE ("Mutex::tryLock: error=0x%X", res);
120 }
121 return res == 0;
122 }
123
124
125 /*******************************************************************************
126 **
127 ** Function: nativeHandle
128 **
129 ** Description: Get the handle of the mutex.
130 **
131 ** Returns: Handle of the mutex.
132 **
133 *******************************************************************************/
nativeHandle()134 pthread_mutex_t* Mutex::nativeHandle ()
135 {
136 return &mMutex;
137 }
138
139
140